Method and apparatus for dissolving renal calculi



May 2,1967 T.A.DAVlS 3, 6,910

METHOD AND APPARATUS FOR DISSOLVING RENAL 'CALCULl Filed Dec. 20, 1965INVENTOR.

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flgen? v United States Patent 3,316,910 METHOD AND APPARATUS FORDISSOLVING RENAL CALCULI Thomas A. Davis, 1735 SW. Prospect Drive,Portland, ()reg. 97201 Filed Dec. 20, 1963, Ser. No. 332,134 4 Claims.(Cl. 128-227) This invention relates to the dissolution of renalcalculi, and more particularly to a method and apparatus for dis--solving renal calculi with maximum effectiveness, efficiency andsafety.

The removal of renal calculi by dissolution, rather than by openoperation, is of advantage in many circumstances. For example, it hasimportant application in the recurrence of calculi after operativeremoval, when reoperation would be technically diflicult, when fragmentsremain after operative removal, when renal lithiasis complications occurin advanced pregnancy, and in poor operative risks. It is useful whenoperative removal of large staghorn calculi might result in extensivedamage to, or loss of, the kidney, and for the removal of small stonesin minor calyces which cause recurring hematuria and infection but theoperative removal of which might result in unjustifiable parenchymaldamage.

Dissolution of renal calculi has been achieved heretofore by insertingtwo or more ureteral catheters or a double lumen catheter into the renalpelvis and introducing a calculus solvent into the renal pelvis throughone of the catheter lumens while continuously removing the solventthrough the one or more other catheter lumens. This procedure has beenfound inadequate because of experienced disadvantages and dangers.Multiple ureteral catheters may sometimes not be insertable withouthazard due to the restricted size of the ureteral caliber. Smallercaliber catheters become too easily obstructed, and higher pressures arerequired to provide equivalent flow through the circuit of the smallercatheters. T-he outflow catheter frequently becomes obstructed, thusresulting in dangerously increased intrarenal pressures. Even the normalelevated pressure attending the continuous flow of solvent may be afactor in producing ischemic necrosis, as well as absorption of chemicalproducts of the calculus, with resulting hyperphosphatemia. Theintroduction of bacteria into the kidney may result upon breaking of theconnections when it is necessary to open the lumen of the outletcatheter by hand syringe irrigation.

The foregoing and other deleterious factors have been "encountered andreported, with the result that the proce dure has been abandoned.

Accordingly, it is the principal object of the present invention toprovide a method and apparatus for the effective, efficiency and safedissolution of renal calculi, with the elimination of the foregoingdeleterious and dangerous factors.

Another important object of this invention is the provision of a methodand apparatus for dissolving renal calculi, which involves the use ofonly one ureteral catheter to perform the 'dual function of introducingthe cal culus solvent to and removing it from the renal pelvis.

Still another important object of the present invention is the provisionof a method and apparatus for dissolving renal calculi, which method andapparatus insures the limitation of intrarenal pressure to a safe level.

A further important object of this invention is the provision of amethod and apparatus for dissolving renal calculi, which method andapparatus requires minimum professional attention, being operable withcomplete effectiveness and safety by the patient with a minimum ofinstruction.

A still further important object of this invention is the 3,3lli,910Patented May 2, 1967 provision of a method and apparatus for dissolvingrenal calculi, which method and apparatus involves a minimum ofequipment, all of which is commercially available.

The foregoing and other objects and advantages of this invention willappear from the following detailed description, taken in connection withthe accompanying drawing in which:

FIG. 1 is a foreshortened view in side elevation of apparatusexemplifying and embodying the features of the present invention;

FIG. 2 is a fragmentary plan view, partially sectioned and on anenlarged scale, showing details of construction of a conventionalcatheter; and

FIG. 3 is a fragmentary foreshortened side elevation of a modified formof apparatus embodying the features of this invention.

In its basic concept, the present invention involves the introductioninto the renal pelvis, through a single catheter, of a quantity ofcalculus solvent not substantially exceeding the intrarenal capacity,retaining said solvent therein for a period of time suiflcient to effectat least partial dissolution of the calculi, removing said quantity ofsolvent from the renal pelvis through said single catheter, andrepeating the foregoing sequence of steps over a period of timesuflicient to effect dissolution of the calculi.

Among the solvents suitable for dissolving renal calculi are the varioussodium and other alkali metal salts of ethylene diamine tetra aceticacid. Another solvent is known by the trademark Renacidin.

Referring now to the drawing, the apparatus illustrated in FIG. 1includes a supply reservoir adapted to contain a substantial quantity ofcalculus solvent. In the embodiment illustrated, the supply reservoir isin the form of an inverted flask 10 closed at its bottom open end with astopper 12 through which extends a fluid flller tube 14 and an air tube16. The outlet tube terminates at its upper end adjacent the lower endof the flask, and the air inlet tube terminates at its upper endadjacent the upper end of the flask.

The tubes 14 and 16 project downward through the stopper and communicatethrough the respective flexible tubes 18 and 20 with the upper ends ofthe corresponding fluid filler tube 22 and air tube 24, respectively.These tubes extend through a stopper 28 which closes the upper end ofthe measuring flask 30. The air tube 24 terminates at its lower endadjcent the upper end of the measuring flask, and the fluid filler tube22 terminates at its lower end a distance below the air tube. An airvent tube 32 extends through the stopper 28 and communicates the upperend of the measuring flask wit-h the atmosphere. The outer end of thetube 32 is loosely plugged with cot ton or other suitable material 34 toexclude solid contaminants from the measuring flask.

By means of the foregoing arrangement of the tubes,

the solvent in the measuring flask is maintained at a substantiallyconstant level adjacent the lower end of the air tube 24, as is wellknown. The lower constricted open end of the measuring flask 30 isconnected to one end of the flexible tubing 36, the opposite end ofwhich is connected to one leg of a triple branch coupling 33. Althoughthis coupling may take the form of a T, or other configuration, theY-shaped coupling is illustrated merely for convenience.

A second leg of the coupling 38 is connected to one end of the flexibletubing 40 the opposite end of which is connected to the bottom end of anelongated burette tube 42 which, conveniently, is supported by themeasuring flask 30 by tapes 44 or other suitable means. In the preferredarrangement illustrated, the zero graduation on the burette is alignedhorizontally with the established level of solvent in the flask 30, sothat the burette will fill each time to the substantially constant levelof the zero graduation.

The upper open end of the burette is plugged loosely vith cotton orother suitable material 46.

The third leg of the coupling 38 is connected to one end f the flexibletubing 48, the opposite end of which is onnected to one leg of a secondtriple branch coupling t). 5. second leg of this coupling is connectedto one end of he flexible tubing 52, the opposite end of whichcomnunicates with a discharge flask or other suitable drain not shown).

The third leg of the coupling 50 is connected to one rid of a flexibletubing 54, the opposite end of which is onnected to one end of aconventional ureteral catheter 6. The opposite end of the cathetergenerally is closed FIG. 2), and the adjacent end of the internal bore58 f the catheter usually communicates with a pair of loneludinallyspaced openings 60, 62 which extend through he catheter wall atdiametrically opposed positions, to ninimize the possibility ofobstruction, as is well known.

The flexible drainage tube 52 is provided with a draintge control valve64 by which the tube may be closed or )pened. There are many types ofvalves suitable for this urpose, the Davol clamp valve illustrated beingpreferred or its simplicity and ease of operation with one hand. Insimilar manner the flexible infeed tubing 48 is provided vith an infeedcontrol valve 66 for controlling the inroduction of solvent to thecatheter 56 and hence to the 'enal pelvis. The drainage control valve 64and infeed :ontrol valve 66 preferably are located for convenientmanipulation by one hand of the patient, as explained nore fullyhereinafter.

The infeed tube 48 preferably is also provided with a ihutoff valve 68similar to the valves 64 and 66, but posiioned remotely from the patientfor use by the physician 0 either start or stop the treatment.

The flexible tubing 36 connected to the outlet end of he measuring flask30 is provided with'an adjustable valve 70 for regulating the flow rateof solvent from the measurng flask to the burette metering tube 42. Thisvalve is tdjusted to constrict the tubing to the extent that the flow )fsolvent from the measuring flask to the burette (when valve 66 or valve63 is closed) effects filling of the burette :o the zero graduation in asubstantial length of time, for :Xample ten minutes. By restricting theflow to this ex- Lent, it will be apparent that an insignificant volumeof solvent will flow from the measuring flask When the infeed :ontrolvalve 66 is opened to introduce a measured volume at solventrfrom theburette to the renal pelvis. This measured volume of solvent ispredetermined not to sub- ;tantially exceed the intrarenal capacity, andthis volume nay be identified visually by appropriate graduations on ;heburette.

The supply reservoir 19 and measuring flask 30 preferably are mountedupon a mobile or otherwise portable support (not shown) for easytransport of the apparatus to the bedside of the patient. In use, thecatheter 56 is inserted into the renal pelvis, the drainage tube 52 isplaced in a discharge flask or other drain source, and the drainagecontrol valve 64 and infeed control valve 66 are positioned forconvenient access and manipulation by one hand of the patient. Withthese valves closed and the shut off valve 68 open, the physician theninstructs the patient to open the infeed control valve 66 until thelevel of solvent in the burette drops to a predetermined graduation, forexample to the cc. graduation. The patient then is instructed to closethe infeed control valve and to then wait a predetermined time, forexample ten min utes, before opening the discharge control valve 64. Thesolvent thus is retained in the renal pelvis for said ten minutes, orother suitable period of time sufiicient to effect at least partialdissolution of the calculi. The discharge control valve 64 then isopened for a period of time, for example two minutes, to permit drainageof the solvent from the renal pelvis. Thereafter, the discharge controlvalve is closed and the infeed valve is opened to admit a secondpredetermined volume of solvent from the burette to the renal pelvis, aspreviously explained. This cycle of operation is repeated continuouslyon a prescribed schedule, by the patient during his waking hours, orother- Wise by an attendant.

During the ten minutes or other retention time following the closure ofthe infeed control valve 66, in which the solvent is retained in therenal pelvis to effect dissolution of the calculi, the burette 42 isslowly filled to the zero graduation with solvent from the measuringflask 30. The burette thus is made ready to supply a subsequentpredetermined quantity of solvent to the renal pelvis upon completion ofthe preceding cycle. Upon opening of the infeed control valve 66, thispredetermined quantity of solvent is introduced into the renal pelvis ina relatively short period of time, for example a few seconds, afterwhich the infeed control valve is closed. Because of this relativelyshort infeed time, the solvent admitted from the measuring flask isinsignificant.

Moreover, since the volume of solvent introduced through the renalpelvis from the burette is predetermined not to substantially exceed theintrarenal capacity, intra- {enall pressure is assured of beingmaintained at a safe eve In the embodiment illustrated in FIG. 3 thebottom open end of the measuring flask 34 is connected through aconstricted tube 72 and flexible tube 74 to one leg of a T-coupling 76,a second leg of which is connected to the bottom end of the burette tube42. The constricted tube 72 performs the same function as the adjustableregulator valve described hereinbefore, namely to restrict the flow ofsolvent from the measuring flask 30 to the burette 42 to a degreesubstantially less than the flow of solvent from the burette through thecatheter 56.

The third leg of the T-coupling is connected to one end of the infeedtube 48, the opposite end of which is connected to a three way valve 78.The discharge tube 52 and the catheter tube 54 also are connected tothis valve.

The valve is operable in one position of adjustment to interconnect thetubes 48 and 54 for introducing solvent to the renal pelvis. In a secondposition of adjustment of the valve the tube 54 is closed from both ofthe tubes 48 and 52, and the latter tubes are closed from each other. Ina third position of adjustment of the valve the tube 54 is connected tothe discharge tube 52 for draining the solvent from the renal pelvis.

The valve 78 may be of the manually operable type, preferably capable ofmanipulation by the patient, or it may be of the type operated by amechanical or electrical control device on a predetermined time sequencein accordance with the method and mode of operation of the presentinvention.

The method and apparatus described hereinbefore offer many advantages,among which are the following: The single ureteral catheter may be of alarger size and still be insertable under circumstances wherein aplurality of smaller catheters may be diflicult or impossible to insert.The single larger catheter is more easily maintained in place, detritiscan escape more easily through it, and it is much less likely to becomeplugged. If it does become plugged to discharge, infeed to the renalpelvis is automatically stopped. Since low infeed pressure is employedand the volume of solvent introduced to the renal pelvis on each cycledoes not substantially exceed the intrarenal capacity, there is nointrarenal pressure pain and the chance of trauma to the urothelium,extravasation and absorption of toxic matter is considerably decreased.The repeated emptying of the renal collecting system avoids the constantrenal pelvic residual pool and attendant possibility of bacterial growthoccurring in it, as characterized by the continuous flow method. Thecontinuous back pressure against the renal filtration system, andconsequent extended interference of function, resulting from thecontinuous flow method, is prevented, as is intrarenal pressure ischemiawhich results from continuous increased intrarenal pressure. The lowintrarenal pressures employed in the present invention decreasetraumatic hemorrhage and serous oozing, thus decreasing the possibilityof formation of coherent detritus masses and catheter plugging. Calculiin the infundibuli and minor calyces are exposed more to fresh solventthan by the continuous flow method.

It will be apparent to those skilled in the art that variations may bemade in the method and structural features of the apparatus describedhereinbefore without departing from the spirit of this invention and thescope of the appended claims.

Having now described my invention and the manner in which it may beused, what I claim as new and desire to secure by Letters Patent is:

1. The method of dissolving renal calculi, comprising (a) preparing avolume of calculus solvent predetermined not to substantially exceed thecapacity of the renal pelvis cavity to be treated,

(b) introducing said predetermined volumes of solvent into the renalpelvis cavity,

(c) retaining said solvent in the renal pelvis cavity for e a period oftime sufiicient to efiect at least partial dissolution of the calculi,

(d) simultaneously with said retention period preparing another of saidpredetermined volumes of solvent for subsequent introduction into therenal pelvis cavity,

(e) removing the first named volume of solvent from the renal pelviscavity, and

(f) repeating the steps of introducing, retaining, preparing andremoving subsequent batches of said predetermined volume of solventuntil the desired calculi dissolution is eifected.

2. Apparatus for dissolving renal calculi, comprising (a) a calculussolvent measuring container adapted to receive calculus solvent from asource of supply,

(b) level control means associated with the measuring container formaintaining solvent in the latter at a predetermined level,

(0) a calculus solvent dispensing container,

((1) first conduit means interconnecting the measuring container anddispensing container for delivering solvent from the measuring containerto the dispensing container, 1

(e) means supporting the measuring and dispensing containers forrelative vertical adjustment for adjusting the height to which thedispensing container is to be filled with solvent, which height providesin the dispensing container a volume of solvent predetermined not tosubstantially exceed the capacity of a renal pelvis cavity to betreated,

(f) a ureteral catheter,

(g) second conduit means interconnecting the dispensing container andthe catheter for delivering said predetermined volume of solvent in thedispensing container to the renal pelvis cavity to be treated,

(h) flow restricting means associated with the first conduit means forrestricting the ilow of solvent from the measuring container to thedispensing container to a magnitude substantially less than the flow ofsolvent from the dispensing container to the catheter,

(i) drain conduit means communicating with the oatheter for drainingsolvent from the renal pelvis cavity, and

(j) control valve means in the second conduit means and drain conduitmeans for selectively opening and closing said conduit means,

(k) the control valve means in the second conduit means functioning inone position of adjustment to open the second conduit means to dischargethe contents of the dispensing container into the renal pelvis cavityand in a second position of adjustment to close said second conduitmeans and permit filling of the emptied dispensing container withsolvent from the measuring container automatically to said predeterminedvolume.

3. The apparatus of claim 2 wherein the control valve means are manuallyoperable and are positioned adjacent the catheter for manual operationby a patient being treated.

4. The apparatus of claim 3 wherein the ureteral cath-,

eter has a single lumen which communicates with both of the secondconduit means and drain conduit means.

References Cited by the Examiner UNITED STATES PATENTS 1,633,070 6/1927De Mott 128-274 X 1,710,540 4/ 1929 Hollander 128-227 2,202,163 5/ 1940Mulfold et al 128-214 2,879,767 3/1959 Kulick 128-227 2,919,695 1/1960Kim 128-227 3,216,418 11/1965 Scislowicz 128-214 3,233,609 2/1966 Leucci128-227 FOREIGN PATENTS 69,270 5/ 1958 France.

1,125,547 7/1956 France.

OTHER REFERENCES John H. Neif: Southern Medical Journal, volume 27,Number 4, April 1934, pages 304-305.

J. R. Perdue: Journal of Urology, volume 33, 1935, pages 198-200. J. S.Elliot et al.: Excerpta Medica (Surgery), volume 14, January-June 1960,page 307, abstract No. 1386,

RICHARD A. GAUDET, Primary Examiner.

L. FRINKS, Assistant Examiner,

1. THE METHOD OF DISSOLVING RENAL CALCULI, COMPRISING (A) PREPARING AVOLUME OF CALCULUS SOLVENT PREDETERMINED NOT TO SUBSTANTIALLY EXCEED THECAPACITY OF THE RENAL PELVIX CAVITY TO BE TREATED, (B) INTRODUCING SAIDPREDETERMINED VOLUMES OF SOLVENT INTO THE RENAL PELVIS CAVITY, (C)RETAINING SAID SOLVENT IN THE RENAL PELVIS CAVITY FOR A PERIOD OF TIMESUFFICIENT TO EFFECT AT LEAST PARTIAL DISSOLUTION OF THE CALCULI, (D)SIMULTANEOUSLY WITH SAID RETENTION PERIOD PREPARING ANOTHER OF SAIDPREDETERMINED VOLUMES OF SOLVENT FOR SUBSEQUENT INTRODUCTION INTO THERENAL PELVIS CAVITY, (E) REMOVING THE FIRST NAMED VOLUME OF SOLVENT FROMTHE RENAL PELVIS CAVITY, AND (F) REPEATING THE STEPS OF INTRODUCING,RETAINING, PREPARING AND REMOVING SUBSEQUENT BATCHES OF SAIDPREDETERMINED VOLUME OF SOLVENT UNTIL THE DESIRED CALCULI DISSOLUTION ISEFFECTED.
 2. APPARATUS FOR DISSOLVING RENAL CALCULI, COMPRISING (A) ACALCULUS SOLVENT MEASURING CONTAINER ADAPTED TO RECEIVE CALCULUS SOLVENTMEASURING CONTAINER ADAPTED TO (B) LEVEL CONTROL MEANS ASSOCIATED WITHTHE MEASURING CONTAINER FOR MAINTAINING SOLVENT IN THE LATTER AT APREDETERMINED LEVEL, (C) A CALCULUS SOLVENT DISPENSING CONTAINER, (D)FIRST CONDUIT MEANS INTERCONNECTING THE MEASURING CONTAINER ANDDISPENSING CONTAINER FOR DELIVERING SOLVENT FROM THE MEASURING CONTAINERTO THE DISPENSING CONTAINER, (E) MEANS SUPPORTING THE MEASURING ANDDISPENSING CONTAINERS FOR RELATIVE VERTICAL ADJUSTMENT FOR ADJUSTING THEHEIGHT TO WHICH THE DISPENSING CONTAINER IS TO BE FILLED WITH SOLVENT,WHICH HEIGHT PROVIDED IN THE DISPENSING CONTAINER A VOLUME OF SOLVENTPREDETERMINED NOT TO SUBSTANTIALLY EXCEED THE CAPACITY OF A RENAL PELVISCAVITY TO BE TREATED, (F) A URETERAL CATHETER, (G) SECOND CONDUIT MEANSINTERCONNECTING THE DISPENSING CONTAINER AND THE CATHETER FOR DELIVERINGSAID PREDETERMINED VOLUME OF SOLVENT IN THE DISPENSING CONTAINER TO THERENAL PELVIS TO BE TREATED, (H) FLOW RESTRICTING MEANS ASSOCIATED WITHTHE FIRST CONDUIT MEANS FOR RESTRICTING THE FLOW OF SOLVENT FROM THEMEASURING CONTAINER TO THE DISPENSING CONTAINER TO A MAGNITUDESUBSTANTIALLY LESS THAN THE FLOW OF SOLVENT FROM THE DISPENSINGCONTAINER TO THE CATHETER, (I) DRAIN CONDUIT MEANS COMMUNICATING WITHTHE CATHETER FOR DRAINING SOLVENT FROM THE RENAL PELVIS CAVITY, AND (J)CONTROL VALVE MEANS IN THE SECOND CONDUIT MEANS AND DRAIN CONDUIT MEANSFOR SELECTIVELY OPENING AND CLOSING SAID CONDUIT MEANS, (K) THE CONTROLVALVE MEANS IN THE SECOND CONDUIT MEANS FUNCTIONING IN ONE POSITION OFADJUSTMENT TO OPEN THE SECOND CONDUIT MEANS TO DISCHARGE THE CONTENTS OFTHE DISPENSING CONTAINER INTO THE RENAL PELVIS CAVITY AND IN A SECONDPOSITION OF ADJUSTMENT TO CLOSE SAID SECOND CONDUIT MEANS AND PERMITFILLING OF THE EMPTIED DISPENSING CONTAINER WITH SOLVENT FROM THEMEASURING CONTAINER AUTOMATICALLY TO SAID PREDETERMINED VOLUME.